Under the country’s guardianship system, a male family member – normally the father, husband or brother – must grant permission for a woman’s study, travel and other activities.

But the kingdom appears to be relaxing some norms as part of its sweeping “Vision 2030” plan for economic and social reforms as it prepares for a post-oil era.

Last month a royal decree said women would be allowed to drive. The kingdom is also expected to lift a public ban on cinemas and has encouraged mixed-gender celebrations – something unseen before.

In a rare public appearance last week Prince Mohammed pledged a “moderate” Saudi Arabia, long seen as an exporter of a brand of puritanical Islam espoused by jihadists worldwide.

MBS, as he is well known, promised his kingdom will return to “what we were before – a country of moderate Islam that is tolerant of all religions and to the world”.

His comment, while unveiling plans for a US$500-billion development zone, chimes with his public image of a bold liberal reformer in a conservative country where more than half the population is under 25.